HH 1335 
D8 



8 



•IB 1335 
.08 
*opy 1 



The Improvement of Statistics of 

Cause of Death Through 

Supplementary Inquiries 

to Physicians 



Reprinted from the Quarterly Publications of the American Statistical 
Association, June, 1916 



BY 



LOUIS I. DUBLIN, Statistician 

EDWIN W. KOPF, Chief Clerk 

Statistical Bureau, Metropolitan Life Insurance Company, New York 



* 



ft 



o 



■b 



{ 



^ 



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By Transfer 

NOV 3 1916 



47] Statistics of Causes of Death. 175 



THE IMPROVEMENT OF STATISTICS OF CAUSE 

OF DEATH THROUGH SUPPLEMENTARY 

INQUIRIES TO PHYSICIANS. 

By Louis I. Dublin, Statistician, and Edwin W. Kopf, Chief Clerk, Statis- 
tical Bureau, Metropolitan Life Insurance Company, New York. 



The extension of the registration of vital statistics and the 
consequent increase in the amount of available data on Ameri- 
can mortality have resulted in recent years in the development 
of a critical spirit toward these statistics. When data were 
scant, they were perforce accepted with little or no question; 
today we are justified in inquiring to what extent the returns 
are an accurate picture of the actual conditions. Perhaps 
enough material is now at hand to enable one to separate the 
probably true from the uncertain in our mortality returns. 
This questioning is clearly warranted by the likelihood that 
the sources of our statistics will thus be improved. It is only 
as our basic material is sound that the death rates we quote 
have real value. 

The chief source of error in the statistics of mortality is, of 
course, the uncertainty of the primary diagnosis made by the 
physician certifying to the cause of death. A group of clini- 
cians and pathologists, represented by Cabot,* Oertel,f and 
Emerson,| have in recent years contributed stimulating and 
constructive studies of the general reliability of diagnoses 
made in fatal cases. These writers point out, for example, 
that the acute infections, like typhoid fever, scarlet fever, and 
diphtheria, and those conditions which are usually of long 
duration and present distinct clinical pictures, like pulmonary 
tuberculosis and the external cancers, furnish no special dif- 
ficulties of diagnosis to the physician, and statements with 
regard to them may be accepted without further question. 
On the other hand, bedside diagnoses, even in our best hospi- 

• Cabot, Richard C, M.D.: Diagnostic Pitfalls Identified during a Study of Three Thousand Autopsie, 
Journal Amer. Medical Ass'n, December 28, 1912. 

f Oertel, Horst, M.D.: The Inaccuracy of American Mortality Statistics, American Underwriter, May, 
1913. 

J Emerson, Haven, M.D.: Reliability of Certain Classes of Death Certificates, Amer. Jour. Public 
Health, August, 1915. 



176 American Statistical Association. [48 

tals, of Bright's disease, of cerebral hemorrhage and apoplexy, 
and of certain of the heart affections are very frequently not 
confirmed by autopsy, while other determinative conditions are 
shown to have been the primary cause of death. Relief from 
this fundamental difficulty is not within the control of stat- 
isticians, but will depend entirely upon the improvement of 
autopsy facilities and the general rise of standards of medical 
education. A Committee of the Vital Statistics Section of the 
American Public Health Association is now actively engaged 
in considering the International List of Causes of Death from 
this point of view, registering its conclusions as to those titles 
which can be accepted with considerable certainty even in the 
absence of an autopsy, as against those which must be con- 
sidered as tentative assignments only, unless based on autopsy 
findings. 

The present paper bears on the remedy for a second im- 
portant source of error which is largely within the scope and 
control of statisticians. Fortunately, this remedy can be ap- 
plied at once and surprisingly large corrections in the death 
rate for certain causes can be made available. The method 
of procedure consists in attempting to secure from physicians 
completer statements as to the cause of death, in those cases 
where the returns on the death certificate are given vaguely or 
indefinitely, or where there is evidence that the original state- 
ments do not tell the entire story. Thus physicians often 
report conditions like "acute nephritis" as the cause of death, 
and do not refer at all to the primary condition, such as "scarlet 
fever," "influenza," or "alcoholism," which was present and 
known to them. Again, "peritonitis" is frequently reported 
without reference to the "appendicitis" or to the "puerperal 
septicemia" which may have preceded it. The various forms 
of death by violence are still reported vaguely, and without 
due regard for the statistical requirements of assignment to the 
International List of Causes of Death. Certificates frequently 
do not permit one to determine whether death was due to 
accident, suicide, or homicide, and what was the means and 
character of the injury. 

This report is not the announcement of a discovery in the 
field of statistics. It is simply an attempt to put on record 



49] Statistics of Causes of Death. 177 

the results of a method followed for four years in the Statistical 
Bureau of the Metropolitan Life Insurance Company, in the 
treatment of the industrial mortality experience of that com- 
pany. We have realized that, if our material on the mortality 
of the American working classes is to be utilized to the full, 
every effort must be made to improve the quality of the basic 
data, especially since for many diseases and conditions the 
death rate is decidedly modified by the extent to which the 
query system is applied. The method is essentially that fol- 
lowed by the Registrar-General of England and Wales, and by 
the Division of Vital Statistics in the United States Census 
Bureau. We desire at this point to acknowledge our in- 
debtedness to Mr. George H. Van Buren, Chief of that Divi- 
sion, who aided materially in the introduction of the method 
into our office. Both the English* and the American f bureaus 
have already, in their annuals and in other publications, called 
attention to the changes resulting from their systems of in- 
quiry. A preliminary statement of the results obtained by 
our office appeared in the December, 1913, issue of this Quar- 
terly.! In the present paper we shall discuss the effects upon 
our returns on the basis of the much more extensive data now 
available. It is our hope that this complete statement will 
encourage other workers to similar efforts, and that in this 
way the returns of health departments and insurance com- 
panies may become more accurate and comparable. 

The technical procedure is as follows: The death certificates 
attached to the claim papers are carefully examined, and the 
staff engaged in this work determine whether the statement 
of cause of death given by the physician is satisfactory and 
complete for purposes of assignment. Statements of cause pre- 
senting no difficulty are at once classified according to the 
International List of Causes of Death. Joint causes are classi- 
fied according to the precedents and rules of the International 
Committee, as best exemplified by the methods of the United 

• Regiatrar-General of Births, Deaths and Marriages. Report, 1913, p. LXXIX. 
f Bureau of the Census. Mortality Statistics, 1911, p. 36. 

Bureau of the Census. Mortality Statistics, 1912, p. 23. 

Van Buren, Geo. H.: Mortality Statistics and the Physician, Amer. Jour. Pub. Health, Dec., 1915. 

Emerson, Haven, loc. cit. 
X Dublin, Louis I.; Kopf, Edwin W.: Experiment in the Compilation of Mortality Statistics, this Quar- 
terly, Dec, 1913. 



178 American Statistical Association. [50 

States Census Bureau. Wherever the statement of cause is 
considered unsatisfactory for classification, or where, from 
the statement presented to the Company by the claimant or 
from other available sources, there is an indication that a 
serious condition not mentioned on the certificates has con- 
tributed to the death, or where additional information is 
required before a satisfactory assignment can be made, a letter 
of inquiry, asking for the facts, is sent to the physician. Cleri- 
cal labor is minimized wherever possible through the use of 
form letters. A codified series of questions is employed, and 
the examiners indicate to the typists the question which is to 
be inserted in the form. The following is a copy of one of our 
series of letters sent to physicians : 

New York City 
Dear Doctor: 

This Company is analyzing its mortality experience for the year 191 , 
and in order that we may be able to classify accurately the death of 

who died on , and whose certificate you signed, we 

most respectfully ask you to send us the following information in addition 
to the statement now appearing on the death claim, viz.: 
Acute nephritis 
Additional data desired : 
Kindly indicate the primary cause of the ACUTE NEPHRITIS. Due 
to any contagious or infectious disease (scarlet fever, typhoid fever, etc.)? 
Directly due to alcoholism or exposure? Traumatic? If so, means of 
injury? 

The claim was duly paid by this Company under date of 191 , 

and this desired information will be used for statistical purposes only. We 
are confident that your interest in the advancement of the scientific study of 
Causes of Death will prompt you to comply with our request, and we beg 
you to accept our thanks. A stamped envelope is enclosed for your reply. 
Very respectfully yours, 

Statistician. 

(Please answer here) 
15 

At first we proceeded cautiously, inquiring only as to the 
means and character of the injury in cases of ill-defined violence. 
We also asked for the causes for the relief of which operations 
were performed (when expressions such as "operation," "sur- 
gical shock," or "laparotomy" were reported with no addi- 
tional data), the causes contributing to "peritonitis," and the 



51] 



Statistics of Causes of Death. 



179 



more exact location of cancers and tumors. We asked for 
additional information when the terms were "dropsy," "heart 
failure," and others of like character included in the designa- 
tion "Ill-defined Diseases" in the International Classification. 
The scope of our questions has since been much extended. 
The following questions indicate the lines along which inquiry- 
is now made: 



Undesirable Returns and Character of Inquiry Made. 



Undesirable Returns. 
1. "Injury," "Gunshot- 
Wound, " " Drowning, ' ' 
"Accidental death," or 
other ill-defined vio- 
lence. 

2. "Operation," "Hysterec- 

tomy," "Laparatomy." 

3. "Peritonitis." 



4 "Acute nephritis. " 



5. "Meningitis," or "Cere- 
brospinal meningitis." 



6. "Apoplexy." 

7. "Paralysis." 



8. "General paralysis of the 

insane." 

9. "Locomotor ataxia." 



Inquiry. 
Was death due to accident, suicide, or 
homicide? If accident, what kind of 
accident was the primary cause of 
death (steam railroad, street car, fall, 
etc.)? 

What was the cause, for the relief of 
which the operation was performed? 

Was the peritonitis secondary to typhoid 
fever? To tuberculosis? To puer- 
peral septicemia? To appendicitis? 
If postoperative, what was the primary 
cause? Was it accidental, suicidal, 
or homicidal? If so, what was the 
means of injury? 

What was the primary cause? Was it a 
contagious or infectious disease (scar- 
let fever, typhoid fever, etc.)? Was 
it directly due to alcoholism or ex- 
posure? Was it traumatic? If so, 
what was the means of injury? 

Was it epidemic? Tuberculous? Was 
it simple meningitis following lobar 
pneumonia, typhoid fever, or any other 
contagious or infectious disease? Was 
it traumatic? If so, what were the 
means and nature of the injury? Was 
it accidental, suicidal, or homicidal? 

Was this a case of cerebral hemorrhage? 

Was it superinduced by cerebral hemor- 
rhage? Was it a case of spinal paraly- 
sis? Of general paralysis of the insane? 

Was it due to syphilis? If so, was the 
presence of syphilis determined by 
history or tests? 

Was it of syphilitic origin? Traumatic? 
If so, what was the means of injury? 



180 



American Statistical Association. 



[52 



10. "Progressive paralysis." 



11. "Tumor." 



12. "Cancer." 

13. "Abscess." 



14. "Burns." 



15. Any terminal condition, 

origin not stated, such as 
"Septicemia," "Con- 
vulsions," or "Hemor- 
rhage." 

16. "Acute cardiac dilata- 

tion," "Heart failure." 

17. "Pneumonia." 



Was it due to a spinal lesion? Was it 
directly or remotely due to cerebral 
hemorrhage? 

Was it malignant? What was its loca- 
tion? 

What was its location? 

What was its location? What was its 
nature and cause? Was it tubercul- 
ous? Traumatic? 

Was death primarily due to burns re- 
ceived in burning building? (Such 
deaths are separately classified.) 

What was the primary cause? 



What was the primary cause? 

Was it lobar, bronchial, grippal, or tuber- 
culous? Was it traumatic? If so, was 
death due to accident, suicide, or homi- 
cide, and what was the means of injury? 



At the present time we are querying about 8.5 per cent, of 
the certificates of death received in our office. Satisfactory- 
replies are obtained from physicians in about three quarters 
of the cases; the proportion varies somewhat with the con- 
dition queried. Changes are made in the classification, as 
the result of inquiry, in about 70 per cent, of the replies re- 
ceived. It is a pleasure at this time to acknowledge our in- 
debtedness to the thousands of physicians whom we have ad- 
dressed, and who, without reimbursement, have put at our 
disposal their time and opinion in order to help in the campaign 
to improve vital statistics. It is an encouraging commentary 
on the scientific interest of the American practitioner that such 
a large return could be received. 

The following table shows the principal titles in which changes 
in assignment were made; it shows the number of deaths 
that would have been assigned to each title without inquiry, 
the number actually assigned after inquiry, and the ratio of 
the latter number to the former. The titles are arranged in 
the increasing order of these ratios. 



53] 



Statistics of Causes of Death. 



181 



TABLE I. 
NUMBER OF DEATHS FROM CERTAIN CAUSES, BEFORE AND AFTER INQUIRY, AND 
PROPORTION OF LATTER TO FORMER, ARRANGED IN INCREASING ORDER OF 
PROPORTIONS. 
Metropolitan Life Insurance Company, Industrial Department; Mortality Experience, 1911-1914. 



Cause of Death. 



International 
List Number. 



Title. 



Deaths 
before 
Inquiry. 



Deaths 

after 

Inquiry. 



Deaths after 

Inquiry, per 100 

Deaths before 

Inquiry. 



185 
117 
066 
061 
046 

062 
186 
067 
119 
020 
094 
045 

092 
081 

120 
028 
009 
156-163 
029, 032-035 
040 

008 
001 
155 
006 
007 
039 

031 
041 

042 

108 
043 

044 
064 
182 
091 
183-184 
010 
A63 
030 
051 
056 
172 
037 
038 
A61 



Fractures (causes not specified) 

Simple peritonitis — nonpuerperal 

Paralysis without specified cause 

Simple meningitis 

Other tumors (tumor3 of the female genital 
organs excepted) 

Locomotor ataxia 

Other external violence 

General paralysis of the insane 

Acute nephritis 

Purulent infection and septicemia 

Pulmonary congestion, pulmonary apoplexy . . . 

Cancer and other malignant tumors of other 
organs or of organs not specified 

Pneumonia (lobar and undefined) 

Diseases of the arteries, atheroma, aneurysm, 
etc 

Bright 's disease 

Tuberculosis of the lungs 

Diphtheria and croup 

Other suicides 

Other forms of tuberculosis 

Cancer and other malignant tumors of the stom- 
ach 

Whooping cough 

Typhoid fever 

Suicide by poison 

Measles 

Scarlet fever 

Cancer and other malignant tumors of the buc- 
cal cavity 

Abdominal tuberculosis 

Cancer and other malignant tumors of the peri- 
toneum, intestines, rectum 

Cancer and other malignant tumors of the fe- 
male genital organs 

Appendicitis and typhlitis 

Cancer and other malignant tumors of the 
breast 

Cancer and other malignant tumors of the skin 

Cerebral hemorrhage and apoplexy 

Homicide by firearms 

Bronchopneumonia 

Homicide by other means 

Influenza 

Other diseases of the spinal cord 

Tuberculous meningitis 

Exophthalmic goitre 

Alcoholism (acute or chronic) 

Traumatism by fall 

Syphilis 

Gonococcus infection 

Cerebrospinal fever 



1,484 
1,180 
3,340 
3,752 

266 

714 

1,456 

2,042 

4,186 

820 

749 

3,650 
27,740 

6,390 
32,854 
60,486 
8,850 
2,660 
6,083 

8,804 
1,995 
6,343 
1,666 
3,137 
3,681 

853 
2,067 

2,679 

4,813 
3,807 

2,089 

574 

21,727 

1,443 

9,133 

792 
3,995 
1,248 
2,656 

368 

1.353 

3,575 

1,322 

50 

138 



545 

711 

2,090 

2,534 

196 

558 

1,158 

1,627 

3,375 

725 

664 

3,279 
26,299 

6,199 
32,745 
60,613 
8,881 
2,674 
6,120 

8,932 
2,025 
6,440 
1,696 
3,216 
3,778 



2,133 

2,769 

5,003 
3,959 

2,195 

604 

23,029 

1,532 

9,708 

848 

4,370 

1,389 

3,024 

433 

1,633 

4,432 

2,350 

115 

536 



36.7 
60.3 
62.6 
67.5 

73.7 
78.2 
79.5 
79.7 
80.6 
88.4 
88.7 



94.8 

97.0 

99.7 
100.2 
100.4 
100.5 
100.6 

101.5 
101.5 
101.5 
101.8 
102.5 
102.6 

103.2 
103.2 

103.4 

103.9 
104.0 

105.1 
105.2 
106.0 
106.2 
106.3 
107.1 
109.4 
111.3 
113.9 
117.7 
120.7 
124.0 
177.8 
230.0 
388.4 



The indefinite title " fractures (cause not specified)" shows 
the greatest reduction in the number of assignments. The 
number of deaths after inquiry is only 36.7 per cent, of the 



182 American Statistical Association. [54 

number originally returned. In view of the fact that the 
number of persons exposed is constant, the decrease in the 
number of deaths is accompanied by a corresponding reduction 
in the death rate. We may, therefore, say that the final death 
rate for this cause was 63.3 per cent, less than the one which 
would originally have been quoted. Such general titles as 
"other external violence" and "cancer of organs not speci- 
fied" were in like manner greatly reduced through the deter- 
mination of the nature of the violence, or of the location of the 
cancer. Considerable reductions were obtained upon inquiry 
into the character of such returns as "paralysis" and "loco- 
motor ataxia"; for in such cases added information with ref- 
erence to blood tests, etc., gave sufficient data upon which more 
definite assignments could be made. On the other hand, a 
large number of causes, especially those referring to the in- 
fectious diseases, show very little change. Tuberculosis of 
the lungs, for example, shows an increase of but .2 per cent. 
The infectious diseases of children, such as "measles" and 
"scarlet fever," give somewhat greater percentages of in- 
crease, 2.5 and 2.6 respectively; these increases were made at 
the expense of terminal conditions, such as "hypostatic pneu- 
monia" and "acute nephritis," which are very often given as the 
causes of death. Cancers of definitely specified organs were 
considerably increased in the number of assignments, with a 
corresponding increase in the rates. Thus " cancer and other 
malignant tumors of the breast," of which there are many 
cases, showed an increase of 5.1 per cent, in the death rate. 
Such socially significant titles as "alcoholism," "syphilis," 
and "gonococcus infection" gave very marked rates of in- 
crease, 20.7, 77.8, and 130.0 per cent., respectively. That we 
could add two thirds as many deaths as were originally 
assigned to "syphilis" is in itself sufficient justification for 
the effort involved by our method. The greatest percentage 
of increase is shown by the title "cerebrospinal fever," which 
was increased from 138 to 536 deaths, or nearly fourfold. 

The more definite titles to which some of the undesirable 
titles were changed are shown in the following table: 



55] 



Statistics of Causes of Death. 



183 



TABLE II. 

ILL-DEFINED CAUSES OF DEATH, AND DEFINITE TITLES TO WHICH RE-ASSIGNED, 

BY NUMBER AND PERCENTAGE OF CHANGE IN CLASSIFICATION. 

Metropolitan Life Insurance Company, Industrial Department; Mortality Experience, 1911-1914. 



Ill-Defined Term 

as Classified 
before Inquiry. 



Title Assigned after Inquiry. 



Number and Per- 
centage of Changes 
in Classification. 




■\T„ m : Percentage 
ber - ' Replies. 



Purulent infection and 
septicemia 

(Total replies, 184.) 



Cancer and other malig- 
nant tumors of other 
organs or of organs 
not specified 

(Total replies, 572.) 



Meningitis 

(Total replies, 1,653.) 



Locomotor ataxia 
(Total replies, 321.) 



Paralysis without speci- 
fied cause 
(Total replies, 1,449.) 



General paralysis of the 
insane 

(Total replies, 956.) 

Organic diseases of the 
heart* 

(Total replies, 714.) 

Diseases of the arteries, 
atheroma, aneurysm, 

(Total replies, 603.) 

Pneumonia! 

(Total replies, 3,005.) 



Total changes from "Purulent infection and septi- 
cemia" 



not speci- 



I "Other diseases of the uterus" 
Puerperal septicemia 
Acute abscess 
Other titles 

Total changes from " Cancer . 

fied" 

Cancer and other malignant tumors of the buccal cavity 
Cancer and other malignant tumors of the stomach. . 
Cancer and other malignant tumors of the peritoneum 
Cancer and other malignant tumors of the female gen- 
ital organs 

Cancer and other malignant tumors of the breast. . . . 

Cancer and other malignant tumors of the skin 

Other titles 

Total changes from "Meningitis" 

I Tuberculous meningitis 
Cerebrospinal fever 
Pneumonia 
Diarrhea and enteritis — 2 years and over 
Other titles 

Total changes from "Locomotor ataxia" 

f Syphilis 

\ Other titles 

Total changes from "Paralysis without specified 



I "Other diseases of the spinal cord" 
Cerebral hemorrhage, apoplexy 
General paralysis of the insane 
Other titles 

Total changes from "General paralysis of the in 

sane" 

J Syphilis 

\ Other titles 

Total changes from "Organic diseases of the heart" 

i Cerebral hemorrhage, apoplexy 

I Pneumonia 

J Other titles 

Total changes from "Diseases of arteries, etc." . 

(Syphilis 
Cerebral hemorrhage, apoplexy 
Other titles 

Total changes from "Pneumonia" 

I Influenza 
Bronchopneumonia 
Lobar pneumonia 
Other titles 



134 

6 
54 

8 
66 

423 

25 
75 
61 

148 

83 

28 

3 

1,234 

294 

363 

79 

62 

436 

163 

148 

15 

1,259 

175 



119 

531 

491 

40 

264 

46 

72 

146 

317 

65 

166 

86 

1,754 

22S 

586 

577 

363 



72.8 
3.3 

29.3 
4.3 

35.9 

74.0 

4.4 
13.1 

10.7 

25.9 
14.5 
4.9 

.5 

74.7 

17.8 

22.0 

4.8 

3.8 

26.4 

50.8 

46.1 

4.7 

86.9 

12.1 

61.1 

5.5 

8.2 



55.5 


51.4 


4.2 


37.0 


6.4 


10.1 


20.4 


52.6 


10.8 


27.5 


14.3 


58.4 


7.6 


19.5 


19.2 


12.1 



* Most of the terms included under the title "organic diseases of the heart are fairly definite. How- 
ever certain expressions like "acute cardiac dilatation" and "cardiac insufficiency are often reported 
when they are only terminal symptoms of other diseases. It is these expressions that are covered by 
our inquiry. . .... . . . 

•(■Assignments to "lobar pneumonia" should be regarded as confirmations of original assignments to 
"pneumonia," rather than as changes. 



184 



American Statistical Association. 

TABLE II— Continued. 



[56 



Ill-Defined Term 

as Classified 
before Inquiry. 



Title Assigned after Inquiry. 



Number and Per- 
centage of Changes 
in Classification. 



Num- 
ber. 



Percentage 
of Total 
Replies. 



Pulmonary congestion, 
pulmonary apoplexy 
(Total replies, 155.) 



Peritonitis — non-puer- 
peral 
(Total replies, 575.) 



Acute nephritis 

(Total replies, 1,935.) 



Other diseases of the 
uterus 

(Total replies, 173.) 



Traumatism by firearms 
(Total replies, 119.) 



Fractures (cause not 
specified) 
(Total replies, 1,045.) 



Other external violence 
(Total replies, 504.) 



Ill-defined diseases 

(Total replies, 442.) 



Total changes from "pulmonary apoplexy" 

Organic diseases of the heart 

Chronic bronchitis 

Pneumonia 

Bright's disease 

Other titles 

Total changes from "Peritonitis" 

Abdominal tuberculosis 

Diarrhea and enteritis — 2 years and over 

Appendicitis and typhlitis 

Salpingitis and other diseases of the female genital 

organs 

Puerperal septicemia 

Other titles 

Total changes from "Acute nephritis" 

Scarlet fever 

Influenza 

Alcoholism (acute or chronic) 

Bright's disease 

Other titles 

Total changes from "Other diseases of the uterus" 

Gonococcus infection 

Cancer and other malignant tumors of the female gen- 
ital organs 

Uterine tumor (noncancerous) 

Cysts and other tumors of the ovary 

Salpingitis and other diseases of the female genital 

organs 

Puerperal septicemia 

. Other titles 

Total changes from traumatism by firearms 

(Suicide by firearms 
Homicide by firearms 
Othertitles 

Total changes from " Fractures (cause not 

fied)." 

Traumatism by fall 

Traumatism by crushing — electric railway 

Traumatism by crushing — steam railway 

Traumatism by crushing — automobiles 

Traumatism by crushing — other vehicles 

Traumatism by other means 

. Other titles 

Total changes from "Other external violence' 

Purulent infection and septicemia 

Traumatism by fall 

Traumatism by machines 

Traumatism by crushing — steam railway 

Traumatism by crushing — electric railway 

Traumatism by crushing — automobiles 

Traumatism by crushing — other vehicles 

. Other titles 

Total changes from "Ill-defined diseases" . . . 

Malaria 

Tuberculosis of the lungs 

Organic diseases of the heart , 

Bright's disease 

Other titles 



speci- 



99 

15 

6 

8 

8 

62 

476 

44 

20 

105 

45 

86 

176 

839 



213 

74 

409 

119 

15 

7 
13 



21 
35 
22 
95 

6 

87 

2 

949 

646 
33 
25 
27 
51 
57 

110 

400 

15 

161 
23 
29 
16 
17 
37 

102 

822 
15 
IS 
83 
21 

185 



63.9 

9.7 
3.9 
5.2 
5.2 

40.0 

82.8 

7.7 

3.5 

18.3 

7.8 
15.0 
30.6 
43.4 

3.5 

3.9 
11.0 

3.8 
21 1 
68.8 

8.7 

4.0 
7.5 
3.5 

12.1 
20.2 
12.7 
79.8 

5.0 
73.1 

1.7 

90.8 

61.8 
3.2 
2.4 
2.6 
4.9 
5.5 

10.5 

79 4 
3.0 

31.9 
4.6 
5.8 
3.2 
3.4 
7.3 

20.2 

72 9 
3.4 
4.1 

18.8 
4.8 

41.9 



57] Statistics of Causes of Death. 185 

Letters were received from physicians in connection with 
1,653 cases originally diagnosed as "meningitis." In 1,234 
of these cases, or 74.7 per cent., the classification was changed 
to other and more definite titles. "Cerebrospinal fever" 
received 22 per cent, of the original "meningitis" returns; 
"tuberculous meningitis," 17.8 per cent.; and "pneumonia 
(lobar and undefined)," 4.8 per cent. The title "paralysis 
without specified cause" was the subject of 1,449 replies; the 
classification was changed in 1,259 instances, or 86.9 per cent. 
The larger proportion (61.1 per cent.) of these "paralysis 
without specified cause" cases were classified under "cerebral 
hemorrhage and apoplexy." "Peritonitis" was changed in 
classification in 476 out of 575 cases, or 82.8 per cent. These 
changes were credited chiefly to the titles "appendicitis and 
typhlitis," "puerperal septicemia," "salpingitis," and other 
diseases of the female genital organs. 

Ill-defined returns of "traumatism by firearms" were 
•changed in 79.8 per cent, of the cases queried. The greater part 
(73.1 per cent.) of these deaths was assigned to the title "homi- 
cide by firearms." "Fractures (cause not specified) " were a 
fruitful source of additions to the class of "traumatism by 
fall"; 646 ill-defined fractures (61.8 per cent.) were so assigned. 

After this examination of the ill-defined terms and the more 
definite titles to which they were assigned, we may proceed 
naturally to the other aspect of the change; namely, to de- 
termine how the mortality is constituted in those causes which 
show an increase in the number of deaths. This is indicated 
by Table III. 



186 



American Statistical Association. 



[58 



TABLE III. 

ADDITIONS TO CERTAIN CAUSES OF DEATH FROM INDEFINITE TITLES, NUMBER 

AND PERCENTAGE CHANGED FROM EACH INDEFINITE TITLE. 

Metropolitan Life Insurance Company, Industrial Department; Mortality Experience, 1911-1914. 



Cause of Death Title 
Receiving Additions. 



Title before Inquiry. 



Additions. 



Number. 



Per Cent. 



Typhoid fever 



Measles 



Scarlet fever 



Whooping cough 



Diphtheria and croup 



Influenza 



Tuberculosis of the lungs 



Tuberculous meningitis 



Total changes to " typhoid fever" 

Simple meningitis 

Organic diseases of the heart 

Pneumonia . 

Other diseases of the intestines . 

Simple peritonitis . 

Acute nephritis. 

Bright's disease. 

Cause of death not specified or ill-defined. 

Other titles. 

Total changes to "measles". 

(Whooping cough. . 
Simple meningitis. 
Bronchopneumonia . 
■ Pneumonia. 

Acute nephritis. . ._ 

I Other titles ! 

Total changes to "scarlet fever". . . 

(Simple meningitis 
Bronchopneumonia 
Pneumonia 
■ Acute nephritis 

Bright's disease 

(Other titles 

Total changes to "whooping cough' 

' Simple meningitis 

Convulsions of infants 

Bronchopneumonia 

Pneumonia. 

Pulmonary congestion, pulmonary apoplexy. 

Acute nephritis. 

Other titles. 

Total changes to "diphtheria and croup' 
Acute endocarditis . 
Organic diseases of the heart . 
Diseases of the larynx. 
Acute bronchitis. 
Bronchopneumonia . 
Pneumonia. 

Diseases of the pharynx 

Acute nephritis 

Other titles 

Total changes to "influenza" 

(Simple meningitis 
Pneumonia 
, Acute nephritis 

( Other titles 

Total changes to "tuberculosis of the lungs' 

' Simple meningitis 

Organic diseases of the heart 

Chronic bronchitis 

Pneumonia 

Cause of death not specified or ill-defined. . . . 

Other titles 

Total changes to "tuberculous meningitis". 

j Meningitis 

\ Other titles 



101 


100 


29 


28.7 


3 


3.0 


5 


5.0 


6 


5.9 


16 


15.8 


21 


20.8 


3 


3.0 


3 


3.0 


15 


14.9 


89 


100.0 


3 


3.4 


19 


21.3 


9 


10.1 


31 


34.8 


13 


14.6 


14 


15.7 


98 


100 


7 


7.1 


4 


4.1 


3 


3.1 


68 


69.4 


5 


5.1 


11 


11.2 


45 


100.0 


12 


26.7 


2 


4.4 


6 


13.3 


14 


31.1 


2 


4.4 


5 


11.1 


4 


8.9 


35 


100.0 


2 


5.7 


2 


5.7 


6 


17.1 


2 


5.7 


4 


11.4 


3 


8.6 


2 


5.7 


10 


28.6 


4 


11.4 


394 


100.0 


40 


10.2 


228 


57.9 


75 


19.0 


51 


12.9 


166 


100.0 


6 


3.6 


6 


3.6 


6 


3.6 


70 


42.2 


16 


9.6 


62 


37.3 


377 


100.0 


294 


78.0 


83 


22.0 



■59] 



Statistics of Causes of Death. 

TABLE III— Continued. 



187 



Cause of Death Title 
Receiving Additions. 



Title before Inquiry. 



Additions. 



Number. Per Cent. 



Syphilis 



Cancer and other malig- 
nant tumors of the 
stomach and liver 



Cancer and other malig- 
nant tumors of the fe- 
male genital organs 



•Cancer and other malig- 
nant tumors of the 
breast 



Alcoholism 



Cerebrospinal fever 



Cerebral hemorrhage, 
apoplexy 



Organic diseases of the 
heart* 



Total changes to " syphilis " 

Locomotor ataxia 

Other diseases of the spinal cord 

Cerebral hemorrhage, apoplexy 

Paralysis without specified cause 

General paralysis of the insane _. 

Diseases of the nervous system other than those speci- 
fied 

Diseases of the arteries, atheroma and aneurysm 

Other titles 

Total changes to "cancer and other malignant 

tumors of the stomach and liver" 

Cancer and other malignant tumors of other organs or 

of organs not specified 
Other tumors (tumors of the female genital organs 

excepted) 

Diseases of the esophagus. . . 
Other diseases of the stomach 
Other diseases of the liver. . . 
, Other titles 

Total changes to " cancer and other malignant tumors 
of the female genital organs" 
Cancer and other malignant tumors of other organs or 

of organs not specified 
Other tumors (tumors of the female genital organs 

excepted) 

Uterine tumor (noncancerous) 
Other diseases of the uterus . . 
. Other titles 

Total changes to "cancer and other malignant 
tumors of the breast" 

I Cancer and other malignant tumors of other organs or 
of organs not specified 
Nonpuerperal diseases of the breast (cancer excepted) 
Other titles 

Total changes to "alcoholism" 

I Simple meningitis 
Acute nephritis 
Cause of death not specified or ill-defined 
Other titles 

Total changes to "cerebrospinal fever" 

I Simple meningitis 

\ Other titles 

Total changes to "cerebral hemorrhage, apoplexy 

I Paralysis without specified cause 
Organic diseases of the heart 
Diseases of the arteries, atheroma, aneurysm 
Bright's disease 
Other titles 

Total changes to "organic diseases of the heart". 

Cerebral hemorrhage, apoplexy 

Paralysis without specified cause 

Acute endocarditis 

Diseases of the arteries, atheroma, aneurysm 

Pneumonia 

Pulmonary congestion, pulmonary apoplexy 

Acute nephritis 

Bright's disease 

Senility 

Fractures (cause not specified) 
Ill-defined organic disease. . . . 
Cause of death not specified or ill-defined 
. Other titles 



1,031 

148 
59 
34 
34 

491 



65 
104 



130 



7 
7 
7 
21 

106 

83 
9 

14 
289 

14 

213 

10 

52 

401 

363 

38 

1,408 

885 

46 

166 

137 

174 

287 

10 

13 

10 

14 

12 

15 

25 

9 

13 
11 
39 
43 
73 



100.0 

14.4 
5.7 
3.3 
3.3 

47.6 

9.3 
6.3 
10.1 



57.7 



7 


5.4 


4 


3.1 


7 


5.4 


13 


10.0 


24 


18.5 



100.0 

77.9 

3.7 
3.7 
3.7 
11.1 



100.0 

78.3 

8.5 

13.2 

100.0 

4.8 
73.7 

3.5 

18.0 

100.0 

90.5 

9.5 

100.0 

62.9 

3.3 
11.8 

9.7 
12.4 



♦See footnote on this title in Table II. 



188 



American Statistical Association. 

TABLE III— Continued. 



[60 



Cause of Death Title 
Receiving Additions. 



Title before Inquiry. 



Additions. 



Number. Per Cent. 



Diseases of the arteries, 
atheroma, aneurysm 



Bronchopneumonia 



Pneumonia (lobar and 
undefined) 



Appendicitis and typh- 
litis 



Bright's disease 



Puerperal state — total 



Puerperal septicemia 



Puerperal albuminuria 
and convulsions 



Total changes to "diseases of the arteries, atheroma, 

aneurysm" 

Other diseases of the spinal cord 

Softening of the brain 

Paralysis without specified cause 

Organic diseases of the heart 

Pneumonia 

Pulmonary congestion, pulmonary apoplexy 

Acute nephritis 

Gangrene 

Senility _ _ 

Cause of death not specified or ill-defined 

Other titles 

Total changes to "bronchopneumonia" 

Simple meningitis 

Pneumonia 

Other titles 

Total changes to "pneumonia" 

Simple meningitis 

Organic diseases of the heart 

Pleurisy 

Simple peritonitis (nonpuerperal) 

Cerebral hemorrhage, apoplexy 

Bright's disease 

Other titles 

Total changes to "appendicitis and typhlitis" 

f Intestinal obstruction 

j Simple peritonitis (nonpuerperal) 

[ Other titles 

Total changes to "Bright's disease" 

Cerebral hemorrhage, apoplexy 

Organic diseases of the heart 

Diseases of the arteries, atheroma, aneurysm 

Pulmonary congestion, pulmonary apoplexy 

Acute nephritis 

Other diseases of the kidneys and annexa 

Senility 

Fractures (cause not specified) 

Ill-defined organic disease 

Other titles 

Total changes to " puerperal state — total " 

Purulent infection and septicemia 

Convulsions (nonpuerperal) 

Pneumonia 

Simple peritonitis (nonpuerperal) 

Acute nephritis 

Bright's disease 

Uterine hemorrhage (nonpuerperal) 

Other diseases of the uterus 

Other titles 

Total changes to " puerperal septicemia " 

I Purulent infection and septicemia 
Simple peritonitis 
Diseases of the uterus 
Other titles 

Total changes to "puerperal albuminuria and con- 
vulsions" 

I Convulsions (nonpuerperal) 
Acute nephritis 
Bright's disease 
Other titles 



126 


100.0 


5 


4.0 


9 


7.1 


9 


7.1 


6 


4.8 


5 


4.0 


4 


3.2 


10 


7.9 


28 


22.2 


10 


7.9 


4 


3.2 


36 


28.6 


660 


100.0 


32 


4.8 


586 


88.8 


42 


6.4 


329 


100.0 


79 


24.0 


72 


21.9 


13 


4.0 


10 


3.0 


10 


3.0 


44 


13.4 


101 


30.7 


156 


100.0 


6 


3.8 


105 


67.3 


45 


28.8 


235 


100 


7 


3.0 


19 


8.1 


13 


5.5 


8 


3.4 


74 


31.5 


12 


5.1 


7 


3.0 


9 


3.8 


16 


6.8 


70 


29.8 


368 


100.0 


54 


14.7 


32 


8.7 


15 


4.1 


87 


23.6 


58 


15.8 


26 


7.1 


4 


1.1 


40 


10.9 


52 


14.1 


189 


100 


50 


26.5 


77 


40.7 


32 


16.9 


30 


15.9 


125 


100 


32 


25.6 


54 


43.2 


26 


20.8 


13 


10.4 



61] 



Statistics of Causes of Death. 

TABLE III— Concluded. 



189 



Cause of Death Title 
Receiving Additions. 



Title before Inquiry. 



Additions. 



Number. Per Cent. 





Total changes to "suicide" 


46 

24 

10 

6 

2 

4 

945 

43 

646 

161 

95 

14S 

7 

87 

15 

16 

23 


100 




Acute poisonings 


52 2 


Suicide 


Absorption of deleterious gases (conflagration excepted) 
Traumatism by firearms. . . . 


21.7 
13.0 




Fractures (cause not specified) 


4.3 




Other titles 


8.7 




Total changes to "traumatism by falling". . . . 
Simple meningitis 


100.0 

4.6 


Traumatism by falling ■ 


Fractures (cause not specified) 


68.4 


Other external violence 


17.0 




Other titles 


10.1 




Total changes to "homicide" 


100.0 




Simple peritonitis (nonpuerperal) . . . 


4.7 




Traumatism by firearms 


58.8 


Homicide — total 


Fractures (cause not specified) . . . 


10.1 




Other external violence 


10.8 




Other titles 


15.5 










Of the 101 cases added to typhoid fever, 28.7 per cent, were 
originally classified as "simple meningitis," 20.8 per cent, 
as "acute nephritis," and 15.8 per cent, as "simple peritoni- 
tis." There were 89 additions to "measles," 98 to "scarlet 
fever," 45 to "whooping cough," and 35 to "diphtheria and 
croup," making an addition of 267 deaths to these four dis- 
eases of childhood. "Acute nephritis" played an important 
part in the original assignment in all of these four diseases, 
but more especially in "scarlet fever," where 68 deaths, or 
69.4 per cent, of the changes, were originally so classified. In 
like manner, "bronchopneumonia" and "pneumonia" (un- 
specified), were the original assignments in many of these con- 
ditions; this applies particularly to "measles" and "whooping 
cough." Except for "diphtheria," the indefinite title "sim- 
ple meningitis" is a convenient cloak for the acute infections 
of childhood. "Influenza" and" tuberculosis of the lungs" 
both received significant additions from the title "pneumonia," 
the former receiving 228 additional deaths and the latter 70. 
Of the total changes to tuberculous meningitis, 294, or 78.0 
per cent., were originally classified as meningitis. 

An analysis of the sources of the additions to syphilis is 
interesting. Of the 1,031 changes to this title, 148 were from 
locomotor ataxia, 491 from general paralysis of the insane, 
and 104 from a large number of conditions, connected for the 



190 American Statistical Association. [62 

most part with spinal lesions. Our inquiries with reference to 
"general paralysis of the insane" have definitely confirmed 
the virtually unanimous opinion of clinicians that this condi- 
tion is syphilitic in origin. So uniform is our finding, that we 
are considering seriously the advisability of discontinuing our 
inquiries into this condition, and assuming the existence of 
syphilis in such cases. 

As might be expected, the additions to "cancers of specified 
organs" are at the expense of the residual title, "cancers of 
organs not specified." The importance of this change is 
obvious in view of the increasing interest in the location of the 
malignant growths. The number of deaths from "acute and 
chronic alcoholism" was increased at the expense of "acute 
nephritis"; 213 out of 289 deaths, or 73.7 per cent., were so 
added. It will be unnecessary to go further into this analysis, 
since the various parts of the table speak for themselves. 

The foregoing tables and text are sufficient to indicate the 
possibilities inherent in the intensive questioning of mortality 
returns. It does not lie within the power of the statistician 
to correct errors which depend upon the diagnostic ability of 
physicians, or upon circumstances which do not permit ade- 
quate opportunity for case observation or for accurate clinical 
or pathological findings. There is, however, a class of errors 
which he can undoubtedly reduce to a minimum. He can 
raise the standard of accuracy in mortality statistics by in- 
viting the physician to give information such as he is able and 
willing to impart. It is reasonable to assume that the physi- 
cian will, at first, have in mind not so much the statistical use 
of the information which he possesses as the immediate and 
uppermost clinical phase of the case. His efforts in the last 
stage of a losing battle against disease or injury are so often de- 
voted to combating serious complications, that he is more than 
likely k) certify only the immediate and not the primary cause 
of death. The statistician can tactfully point out to him an 
error of omission. Experience has demonstrated that, in a 
large proportion of cases, physicians manifest sufficient interest 
in the precision of our vital statistics to supply the additional 
and qualifying statements. As inquiries are made, moreover, 
physicians become more and more aware of the requirements 



63] Statistics of Causes of Death. 191 

of statistical technique in making assignments. An analysis 
of our returns shows an increasing proportion of satisfactory 
statements for certain causes of death. A physician to whom 
an inquiry is once sent will usually not make the same in- 
definite statement in his subsequent certificates of death. 

This means for advancing the accuracy of cause of death 
statistics is at hand in every registration and compiling office, 
and it is hoped that it will soon be adopted by vital statisti- 
cians generally. The fruitful character of the returns, af- 
fecting as they do the basic material of vital statistics, the 
simplicity of the method, and its low cost both in time and in 
money, indicate plainly the desirability at the present time 
of inquiries to physicians as an integral part of the classifica- 
tion of causes of death. Certainly the day has arrived when 
material cannot be admitted into the realm of good vital statis- 
tics unless it has previously been subjected to careful inquiry 
such as we have outlined above. That is the least which can 
be expected, in view of the uncertainty of much of the material, 
due in the first instance to errors of bedside diagnosis uncor- 
rected by autopsy. 



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